69-1409—1 G.H. Rev. 11-02 www.honeywell.com/yourhome
T8600D CHRONOTHERM® IV DELUXE PROGRAMMABLE THERMOSTATS
Printed in U.S.A. on recycled
paper containing at least 10%
post-consumer paper fibers.
Automation and Control Solutions
Honeywell Honeywell Limited-Honeywell Limitée
1985 Douglas Drive North 35 Dynamic Drive
Golden Valley, MN 55422 Scarborough, Ontario
M1V 4Z9
Heating or cooling
come on
momentarily and
shut off
Heat or cool circuit is opening
up or becoming high
impedance.
Add resistor in parallel with load or install interface relay.
System on indicator
(flame=heat,
snowflake=cool) is
displayed, but no
warm or cool air is
coming from the
registers.
Fan operation set for 0 (con-
ventional heat) when it should
be set for 1 (electric heat).
Enter Installer Setup number 2 and reconfigure the fan
operation.
Conventional heating equipment
turns on the fan when the
furnace has warmed up to a
setpoint.
Wait a minute after seeing the on indicator and then check the
registers.
Heating or cooling equipment is
not operating.
Verify operation of heating or cooling equipment in self-test.
Outdoor tempera-
ture not displayeda
Option not activated. Enter Installer Setup number 24 and set to 1. Thermostat must
have OT terminals and a C7089B1000 installed.
Outdoor
temperature
display is incorrecta
Outdoor sensor is connected
incorrectly.
Refer to C7089B1000 Installation Instructions and check wiring
between the thermostat and sensor.
Wrong sensor. Replace sensor with C7089B1000 Sensor.
aSelect models.
Table 6. Troubleshooting Guide. (Continued)
Symptom Possible Cause Action